Multilevel spray control

ABSTRACT

An electronic control circuit is disclosed for controlling the operation of a paint spray system of the type having a spray station having at least one spray gun assembly and one spray gun thereon and a conveyor means for transporting objects of diverse geometry past the spray station.

United States Patent Porter 5] Feb. 29, 1972 [54] MULTILEVEL SPRAY CONTROL 2,971,492 2/l961 Enssle ..118/2 [731 Assignee: Amtron, lnc., Midlothian, [11. 3,1 2,7 6 7l 65 PC6118 et al v ..1 18/2 X 3,198,351 3/1965 Paglee 40/1725 X [22! M! 3,223,255 12/1965 Graybeal el al.... ..2|4/|| 2 APPL 52 5 3,356,061 12/1967 Wiggins ..118/2 3,444,839 5/1969 Ellul ..118/2 3,496,907 2/1970 Morison ..1 18/2 [52] US. Cl ..340/172-5, 118/2 [51] Int. Cl ..GUSb 23/02, G051) 1 1/26, C051! 1 1/32 Primary Examiner-Gareth D. 5118! [531 Field of Search ..340/172.5; 118/2, 9, 1 1; Assistant Examiner-Jan E. Rhoads 21 /1 1; 2 7. 63 Attorney-Hume, Clement, Hume & Lee

{56] References Cited [57] ABSTRACT UNlTED STATES PATENTS An electronic control circuit is disclosed for controlling the operation of a paint spray system of the type having a spray 3,521,598 7/1970 Straw ..1 18/2 station having at least one Spray gun assembly and one Spray 3559977 1/1971 Porter-m WW328/39 gun thereon and a conveyor means for transporting objects of 3,593,308 1 Pagan di geometry t th spray t ti 2,754,795 7/1956 Enssle.... ..118/2 2,961,990 1 1/1960 Wruck ..1 18/2 26 Claims, 7 Drawing Figures Ft'f/lfiOf/fO/F I mp W Maw:

Alf/Mil mm:

#1 ,m A t/PM)?! mwm MIMI! mm: M1 4 1; zmpwmme Mal/1H? mmsvm. SPRAY coN'raoL BACKGROUND OF THE INVENTION The present invention relates generally to spray coating systems of the type having a vertically reciprocating spray station and a conveyor means for transporting objects of diverse geometry past the spray station. More particularlyI the invention is directed to a new and improved electronic control apparatus for automatically regulating the operation of the spray gun assembly in accordance with the sensed dimensions and the horizontal position of the various objects to be coated and in accordance with the vertical position of the spray gun assembly. Those concerned with the development of a paint spray control system have long recognized the need for developing a spray control which utilizes a horizontal and vertical recognition concept and which provides automatic operation of spray guns with a minimal waste of coating material.

Several known prior art spray gun control systems are able tosensethehorirontaldimensionandpositionoianobjectto be sprayed at an area remote from the spray station. Inaddition, one such a control system also includes means for measuringtheverticsi heightoftheparttobesprayedandisdisclosed by John C. Pagan in copending United States Pat. application Ser. No. 771,865, filed Oct. 30, 1968, now U.S. Pat. No. 3,593,308 and assigned to Amtron. Inc. This spray control system includes a 'means for developing a digitized signal representative ot the horizontal and vertical dimension of an object to be sprayed. The digitized information is then fed into a shift register and the output of the shift register actuate! the spray guns on the spray gun assembly. Means are also provided for nroving the spray gun aaembly between two vertical limits. In order-to accurately measure the vertical dimensions of the part, the above-identified application utilizes a plurality of shift registers, one shift register being associated with each incremental vertical zone. For example if ten vertical rones are used it is necessary to utilize shift registers. Naturally, the utilization of a plurality of shift registers has proven to be expensive.

SUMMARY OF THE INVENTION The present invention comtitutes an improvement over United States Pat. application Ser. No. 771.865. filed Oct. 30, 1968. now Pat. No. 3,593,308 and amigned to Arntron, inc. The present invention provides a spray control system which embraces all of the advantages of the aboveidentifled application but which is more economical to manufacture. To attain this. the present invention utilizes a single memory storage matrix for storing a digitized information signal which is related to the dimensions of the object. The memory storage matrix replaces the need for the plurality of shift registers utilised in the copending application and furthermore, a single memory storage matrix may be utilized for sensing 16 vertical zones thereby greatly reducing the cost of the invention. In addition, other features are disclosed which constitute improvements over the copending application.

Therefore, an object of the present invention is the provision of a paint spray control system in which various objects are sensed at a position remote from the spray station and the information representative of the horizontal and vertical geometry of the part is effectively stored within a storage matrix until the object is advanced to a position adjacent to the spray control station.

Another object is to provide a control apparatus for a spray coating system which correlates the vertical position of the spray gun assembly with the dimensions of the part to be sprayed and which actuates the spray guns only when the part to be sprayed is of a proper dimension and in the proper pcsition with respect to the spray gun assembly.

A further object is the provision of a control apparatus for a spray coating system utilizing a conventional XY memory matrix which is addressed to function in a manner similar to a shift register.

system and a control apparatus therefor, which a capable of modular construction.

Otherobjectsandmanyoftheattendantadvantagesotth'u inventionwillberesdilyappreciatedssthesamebecomes better understood by references to the following detailed description when considered in connection with the accessr y m sr- BRIEF DESCRIPTION OF THE DRAWINGS FlOJisadisgrammaticrepresentationotaapraycoating systemempioyingacontrolapparatmconstructedinaccordancewlththeteachingsottirepresentinvention.

Flodisagraphicalrepresentationcorreladngthehorisontalpositionsofthespraygunswiththeverticalsensingzones.

Flojisaschernaticdiagramshowingtheverticalzonesassociatedwiththespraygunslembly.

Flfllisablockdiagramoftheelectroniccontrolap paratusutilizedinthespraycoatingsystemshowninFlG.l.

FlG.5isablockdiagramottheinputrnoduleshownin FlGSJansH.

Flflfiisahloclrdiagramottl'rernemorymoduleshownin FlGSJand4.

Fl(i.7issblockdiagrarnofthereciprocatormoduleshown inFlGS.land4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referringnowtothedrawingswhereinlikerefereneenumeralsdesignatelikeorcorrespondingpsrtsthroughoutthe several viewnthereisshowninFiG. laspraycoatirrgsysterrr 10 comprising a conveyor means such as a conventional overhead chain conveyor generally denoted by the reference rrumeral llObjectsofdiversegeornetrylarearspendedby hooksorthelikefromtheconvcyoratspacedirrtervalsalong itslength.Theconveyor lltransportstheobjectaunderthe influence of a conventional drive system including a drive sprocket 16 toward a spray station generally denoted by the reference numeral 18. A transducer 17 is connected to the drivesprocltet ltiandgeneratesasigrralviaalead "connected to an electronic control circuit 40.

Thespraystation 18 may generallycompriseaphrralityol' reciprocatorunits20,20a.etc. Itwillberecomrizedthatwlfle FIG. i onlyshowstworeciprocatorslflandmanynurnber ofreciprocatorsmaybeutilizedinaccordancewiththe teachings of the invention. The reciprocators 20 and 20a may eachbcpairedsothat reciprocatorliimaycoatthefirstside of object 14 and reciprocator 200 may coat the reverse side. Each reciprocator unit 20. 20a, etc.. is conventional and may comprise a spray gun assembly or carriage 22, each having four laterally spaced spray guns 24, 24a, 24b and 24c as schematically represented in the drawings. The spray gun assembly llisadaptedtobeverticallyreciprocatedonaguidetrack 26 between spaced upper and lower limits 28 and 30. respectively. The spray gun assembly or carriage 22 is driven between the spaced vertical limits 28 and. 30 by a conventional chain drive mechanism generally shown as metal 32. The chain drive mechanism includes a drive sprocket 34 having attached thereto a transducer 36. The electrical output from transducer 33 is connected via lead 38 to the electronic control circuit in accordance with the present invention, the spray coating system further includes a sensor means generally designated as numeral 42 comprising a light source 44 and a plurality of photocells 46, 46a, 46b, 46c, etc. The sensing means 42 is preferably positioned a predetermined distance in advance of the spray station IS. The plurality of photocells 46a, 46b, 46c, etc., are vertically spaced from each other and form a plurality of sensing zones. Each sensing zone is defined as the distance between two consecutive photocell elements such as the distance between photocells 46a and 46b. An eclipse of the light source by the movement of an object 14 passing between the light source and the photocell, develops signal information on a lead 48 in a conventional manner. This signal information is coupled to the input of the electronic control circuit 40.

The photocell arrangement or sensing means 42 in the present embodiment senses the presence or absence of an object and thereby, is able to provide information representative of the vertical dimension or height of the object 14. An effective measure of the horizontal dimension, i.e., the width of the object 14 in the plane of the photocell, is provided by the transducer 17 attached to the drive sprocket 16. The transducer 17 may comprise conventional reed switch plus a generator which is geared to the drive sprocket 16 of the conveyor as schematically denoted in the drawing, and is adapted to develop a reference signal pulse on its output lead I9 for each incremental unit of travel of the conveyor 12. For example, as the conveyor 12 moves, it drives the rotary transducer 17. The glass reed switch yields a fixed (e.g., 12) number of closures per revolution. With suitable gearing, the closures can represent any convenient conveyor travel dimension (e.g., 3 inches). This transducer signal establishes the horizontal increments and by connecting the reed switch of the transducer 17 through a suitable contact control circuit (FIG. 5), shift pulses which are compatible with high-speed logic systems are generated along the lead 19. A suitable switch contact control system is disclosed by Virgle E. Porter in copending United States Pat. application Ser. No. 661,894,1iled Aug. 21, I967, now US. Pat. No. 3,559,077 and assigned to Amtron, Inc.

The entire length of travel of the conveyor 12 may be electronicaliy represented by the increment signals generated by the transducer I7. Throughout the operation of the spray control system It], it is necessary to utilize the horizontal increments. Each spray gun 24, 240, etc, in FIG. I is a given horizontal distance from the sensing means 42. This distance may be designated in increments. For example, the graph in FIG. 2 shows that spray gun 24 is 5l increments (153 inches) downline from sensing means 42 while spray gun 24c is 60 increments I 80 inches) downline from sensing means 42.

The electronic control circuit 40 is adapted to effectively and temporarily store signal information representative of the horizontal and vertical dimensions of the object M to be sprayed. In the present embodiment, this dimensional information is disclosed by the combined signal information on the input leads 48 and 19. The electronic control circuit 40 processes the information received and compares the part dimension and horizontal position along the conveyor belt with the position of the individual gun assemblies 22, 220, etc. This latter information regarding the position of the individual gun assemblies is conveyed to the electronic control circuit 40 via the leads 38, 380, etc. This information is then compared with the information relating to the dimensions of the object 14 and its position along the conveyor 12 and when a proper relationship exists (i.e., the object 14 is horizontally positioned in front of the reciprocator units 20 and is of a dimension which coincides with the vertical position of the spray gun assembly 22), a signal is generated on lead 50 or 500, etc., which then actuates the individual spray guns 24, 24a, etc, thereby spraying the object. As will be explained in greater detail below, if an object passes in front of the reciprocator unit 20 and if the vertical position of the spray gun assembly 22 is such that the spray guns are not in proper position with respect to the object, no signal would be generated on lead 50 and the guns would not spray the part. Therefore, in order to insure that the entire object 14 is sprayed, it is normally desirable to employ a plurality of reciprocator units so that the entire object will be sprayed eventually, regardless of the ver' tical positions of each of the spray gun assemblies 22. 220, etc.

It will be recalled that the sensing means 42 is adapted to define a plurality of sensing zones. In a like manner the vertical travel of the spray gun assembly 22, 220, etc., is also divided into spray zones so that the instantaneous position of each spray gun 24, 240, etc, may be determined. Establishment of the spray zones is based upon the height of the reciprocator unit 20 and the height of the sensing means 42. The height of the reciprocator is divided into vertical inert: ments in a manner similar to the horizontal increments. The height of each spray zone is equal to the height of its corresponding sensing zone. It is not necessary, however, that the zones each be the same height. For example, zone I may be 5 inches and zone 7 may be 12 inches. FIG. 2 shows the vertical spray zones 1 to [0 which correspond to the vertical sensing zones.

Referring to FIG. 3 in conjunction with FIGS. 1 and 2, there is shown a schematic diagram of the vertical path of the spray gun assembly 22. The spray gun assembly 22 is driven by the drive sprocket between upper and lower limits 28 and 30, respectively. A limit switch (not shown) is provided at the lower limit 30 and generates a signal on a lead 27 when the spray gun assembly 22 reaches its bottom limit 30 of travel. In addition, a continuous pulse signal is generated by the transducer 36 being driven by the reciprocator drive sprocket 34 and represents the instantaneous vertical position of the spray gun assembly 22. The pulses from the transducer 36 define vertical increments and in the preferred embodiment, each pulse or vertical increment is adapted to equal 1 inch. It will be remembered that each horizontal increment was representative of 3 inches. However, these relationships are only preferred but are not critical. FIGS. 2 and 3 show that no zones have been assigned to the turn around portions 21 nd 23 of the reciprocator unit 22. Zone 1 has been defined as starting seven increments or 7 inches above the bottom limit of travel 30. In the preferred embodiment, the total distance of vertical travel is 96 inches and the zones occupy inches; however, this is purely arbitrary. It will also be noted in FIG. 3 that the upward zones on the left differ from the downward zones on the right. This is commonly referred to as towing and will be described in detail below.

Referring now to FIG. 4, the electronic control circuit 40 comprises an input module 60, a memory module 80 and a reciprocator module 120. It will be noted that a memory module 80 is associated with each reciprocating unit. For example, memory module 800 is associated with reciprocator unit 200. It will also be noted that reciprocator module I20 is also associated with each reciprocator unit. However, as will be explained below, only a single input module is necessary. The single input module may be used in conjunction with a plurality of memory modules and reciprocator modules. The only requirement is that the power supply 52 be powerful enough to drive the several modules.

Connected to the input of the input module 60 is a lead 48 from the sensor means 42 and a lead 19 from the conveyor transducer I7. A source of electrical power, schematically shown as numeral 52, is also connected via a lead 53 to the input module 60. Also connected to the input of input module 60 is a lead-lag manual control circuit 62. In many coating ap plications, it is desirable to turn the spray guns on just before the part arrives in order to coat the corners or front edges. Lead-lag manual control circuit 62 provides for this. Furthermore, it is often desired to have a similar control for use on the lagging edge of the part and the lead-lag of manual control circuit 62 provides for the enabling of the spray guns for a predetermined amount of time which is greater than that indicated by the signal information generated by the sensor means 42. Lastly, lead-lag manual control circuit 62 also provides for an underspray characteristic. This is used when it is desired to allow a portion of the object 14 to go uncoated. In this manner, even though the sensor means 42 indicates that the spray gun should be actuated, the lead-lag manual control circuit will prevent actuation thereby enabling the object 14 to pass uncoated for a predetermined distance.

The output from the input module 60 is fed to the input of the memory module 80. The memory module 80 is used to store the information representative of the dimensions of the object to be sprayed as well as its horizontal position along the conveyor. The memory module 80 is always paired with a reciprocator module 120 and must be used in conjunction therewith. The data stored in the memory module 80 is received from the input module 60. A downline patch 82 is also provided to the input of memory module 80. The downline patch electrically represents the horizontal position in increments of each of the spray guns 24, 24a, 24b, as will be explained in conjunction with FIG. 6. Lastly, the output from the memory module 80 is fed to the input of the reciprocator module 120. Also connected to the input of the reciprocator module 120 are leads 27 and 38 which provide signal information indicative of the vertical position of the spray gun assembly 22. A zone patch 122 is provided to the input of the reciprocator module 120 in order to electrically indicate when the reciprocator passes from one vertical spray zone to the next. The data from the memory module 80 is compared with the vertical location of the spray gun assembly 22 as it moves vertically up and down between its limits 28 and 30. When the memory module 80 and the reciprocator module 120 indicate that the object 14 is in the correct relative position with respect to the spray gun assembly 22, a signal is generated along lead 50 which actuates a solid-state relay thereby actuating a spray gun 24, 24a or 24b, etc.

It can also be seen from FIG. 4 that the output from memory module 80 is also transmitted via lead 81 to the input of a second memory module 80a. Memory module 80a is associated with reciprocator unit 200. The output from the memory module 80a is transmitted to the input of a reciprocator module 120a which in turn controls the spray gun associated with spray gun assembly 220. If it is desired to have more than two reciprocator units 20 and 20a, the output from the memory module 80a would then be connected to another memory module 80b (not shown) and the output from the memory module 80b would be fed to a reciprocator module 1211b (not shown). From this, it can be seen that any number of reciprocator units 20 having spray gun assemblies 22 may be provided. However. it is to be remembered that each reciprocator unit has associated with it a single memory module and a single reciprocator module. As mentioned previously, onJy a single input module 20 (having a large enough power supply) is required regardless of the number of memory modules 80, 80a, 80b, etc., reciprocator modules [20, 1200, 120b, etc., and reciprocator units 22, 22a, 22b, etc.

A more detailed understanding of the spray coating system may be had by reference to the exemplary electronic control circuit 40 illustrated in FIGS. 4 through 7. As shown, the electronic control circuit 40 comprises an input module 60, a memory module 80, and a reciprocator module 120. It will be recognized that one memory module and one reciprocator module will be associated with each reciprocator unit which make up the spray station 18. For simplicity and clarity of explanation, only one memory module and one reciprocator module are shown and furthermore, the control circuit shown in FIGS. 4 through 7 is used to actuate only four guns on a single spray assembly 22. it will be recognized that any number of spray guns and spray stations may be utilized and control circuit 40 would be enlarged to encompass these added spray guns and spray stations.

The input module 60 comprises N photocell amplifiers 64. One photocell amplifier 64 is associated with each of the photocells 46a. 46b, etc, (FIG. 1). The output from each photocell amplifier 64 is fed into a shift register 66. One shift register is utilized for each photocell 46, 460, etc., in the sensor means 42. Referring briefly to FIG. 1, the photocells 46, 46a, 46b, etc, are arranged so that certain of these are eclipsed as the objects to be coated 14 pass by on the conveyor 12. The number of photocells eclipsed is a measure of the part height. As mentioned above, the distance between each cell represents a sensing zone. The cells are connected to individual photocell amplifiers 64 which then deliver information bits to the input of their respective shift registers 66. in the preferred embodiment, each of the shift registers 66 comprise a nine-stage shift register having a single-stage J-K flipflop 68 serially connected to two four-stage shift registers designated as a lagging edge register 70 and a leading edge re gister 72. Both the lagging edge register 70 and the leading edge register 72 are four-stage conventional shift registers. The output from the photocell amplifier 64 is fed into the input of the J-K flip-flop 68. In addition, the output from the switch contact control circuit 15 associated with the rotary transducer 17 is also fed into the .l-K flip-flop 68. As mentioned above, the switch contact control circuit 15 is fully disclosed in copending application Ser. No. 661,894, filed on Aug. 21, i967, and assigned to Amtron, Inc.

As the conveyor 12 moves, it drives the rotary transducer 17 which consists of a glass reed switch, a permanent magnet and spoked rotating disc. This arrangement, as mentioned previously, yields a fixed number of closures per revolution and with suitable gearing, the closures may represent any convenient conveyor travel dimension such as 3 inches. This establishes horizontal increments and by connecting the reed switch through the switch contact control circuit 15, shift pulses are fed into the J-K flip-flop. The shift pulses initiate a rou tine to be described later and also clock the J!( flip-flop 68.

if the photocells 46, 46a, 46b, etc, previously referred to, are dark thereby being eclipsed, then associated J-K flip-flops 68 are maintained in a set or "one condition. Shift pulses from the switch contact control circuit 15 then clock the .l-K flip flop 68. Subsequent stages of the shift register 66 then respond to the serial data representing the dimension of the object 14.

The remaining eight stages of the shift register 66 comprise a leading edge register 72 and a lagging edge register 70. In many coating applications, it is desirable to actuate the spray guns just before the object arrives in order to coat the corners or front edges. The leading edge manual control 62" established this adjustment and may comprise a rotary switch having several positions numbered 0, l, 2, 3, etc. These numbers represent horizontal increments of off-spray control. Assume an object is three increments wide, if the leading edge manual control 62" is set for 2, spraying will persist for five increments assuming that there was "0 set on the identical lagging edge manual control 62'. These controls 62' and 62" in essence supply additional "bits" of information into the shift register 66. Thus, both the lagging edge register 70 and the leading edge register 72 supply additional bits of information to the memory module in order to control the amount of spraying being done independent of the actual dimensions of the object.

Data bits from the last stage of the leading edge register 72 of the shift register 66 is made available to the input of the memory module 80. More specifically, the bits of infonnation which are representative of the vertical dimension of the object 14 as sensed by the photocells 46, 460, etc, and the horizontal dimension of the object and sensed by the transducer l7 and the eclipsed photocells are made available to a series of write gates 84 which are used in conjunction with an XY matrix or main memory 86. The write gates 84 are conventional and in the preferred embodiment comprise a triple three-input NOR gate. Three triple threeinput NOR gates are utilized for each sensing zone.

The main memory 86 is a conventional XY matrix and may be made up of four 16-bit scratch pad memories for each sensing zone. For ease of construction, these four ltS-bit scratch pad memories associated with each zone may be packaged as a single printed circuit board, one printed circuit board being associated with each sensing zone. Connected to the output of each printed circuit board are four buffer memories 88, 88a, 88b, 88c. Buffer memory 88 is associated with spray gun 24, buffer memory 88a is associated with spray gun 24a, buffer memory 88b is associated with spray gun 24b an buffer memory BBC is associated with spray gun 24c. If there are 10 zones, there are l0 buffer memories associated with each spray gun. In the preferred embodiment, each of the buffer memories is conventional and comprises dual D flipflop circuits.

In addition to the write gates 84, the main memory 86 comprises a flip-flop 90 which is connected to the output of switch contact control circuit and a sequencer clock 92 connected to the output of the flip-flop 90. The sequencer clock 92 is used to sequence a routine sequencer or counter 94. In the preferred embodiment, the routine sequencer 94 may comprise a conventional divide by 16 counter.

As each shift pulse occurs on the lead 89 connecting the switch contact control circuit 15 to the flip-flop 90, a memory routine is initiated. This routine is set up by the routine sequencer 94 as well as the flip-flop 90 and the sequencer clock 92. When a shift pulse occurs, which signals the start of the routine, the flip-flop 90 is set. This flip-flop then enables the sequencer clock 92 which runs until the flip-flop 90 is reset. The flipflop 90 is reset only after the routine sequencer 94 counts in counts after its initiation. The sequencer clock 92 is adapted to provide a clock pulse every i millisecond. However, this is arbitrary, and the response time of the routine sequencer 94 is the only limiting factor.

The output of time slots 0, 2, 4, 6 and 8 of the routine sequencer 94 are connected to a flip-flop 96 which in turn is connected to a l0-microsecond downline clock 98. The output from the downlinc clock 98 is fed to an address counter [00 and to a downline counter 104. The address counter in the preferred embodiment may comprise a conventional divide by 64 counter and decoder while the downline counter 104 may comprise a conventional divide by 100 counter and decoder. The capacity of the address counter 100 is arranged to be slightly greater than the distance in increments from spray gun 24c, the furthest downiine from the sensing means 42. Briefly referring to FIG. 2, it can be seen that spray gun 24c is 62 increments downline from the sensing means 42 and therefore, the address counter 100 is a divide by 64 counter. The output lead l0l of the address counter 100 is connected to the main memory 86 and is used to address the main memory 86. A downline patch 82 is connected to the output lead 105 of the downline counter 104. As mentioned previously, downline patch 82 represents the downline location in increments of each of the spray guns 24, 24a, 24b and 24c. For example, the downline patch may comprise a series of leads 83, 83a, 83b and 83c, associated with its respective spray guns connected to the output terminals of downline counter 104 equal to increments 51, 54, 57 and 60 (see FIG, 2). In addition, an additional patch 85 is provided to detect when the downline counter has reached 65 in its count. Patch 35 in the preferred embodiment may comprise a dual four-input expandable NOR gate. When the downline counter has reached 65, the downline counter 104 is reset to zero thereby initiating a new cycle. The downline patch 82 in essence identifies when the counter has stored enough counts to represent the spray guns downline location from the sensing means 42. In the preferred embodiment, it has been assumed that the downline end of the reciprocator unit 22 is 64 increments downline from the sensing means 42 and therefore, when the downline counter 104 reaches the number 65, it can safely be assumed that the object 14 has passed beyond the reciprocator unit and thus, the downline counter can be recycled to further interrogate the main memory with regard to an additional object 14.

Briefly, before describing in detail the method in which digitized information representative of the dimensions of the object to be coated is fed into the main memory 86 and the manner in which this main memory 86 is interrogated, the physical description of the reciprocator module will be discussed. The output 118 of each of the buffer memories per zone 88, 88a, 88b and 886 are respectively fed into the reciprocator module !20. The output of each buffer memory 88, 88a, etc., is fed to the input of its respective zone gate I24, 124a, l24b and l24c. A zone gate is provided for each buffer memory. The output from each of the zone gates is fed to a gun-actuating control circuit 126, 1260, i261; and 1264:. The gun-actuating control circuits 126, 1260, etc., are conven' tional power circuits which may be used to energize the solenoid of the individual spray guns whenever a signal is present on their respective input leads 125, 1250, l25b, etc. A single gun-actuating control circuit is provided for each spray gun. A signal will only be present on leads 125 when a signal is received from the output of the zone gates 124. The zone gates 124 in the preferred embodiment may comprise conventional coincidence logic gates and in order to receive an output, it is required that there be a signal from both the lead "8 as well as a signal on a lead 128. The lead 128 comes from the output of the zone patch 122. As mentioned previously, the zone patch [22 defines the vertical spray zone in which the spray assembly 22 is currently situated at a given time. If a signal is present on lead "8 indicating that photocells 46 and 46a (zone 1) were eclipsed by the object 14 and if a signal is present on lead 128 corresponding to zone 1, the spray gun 24 will be actuated.

It will be remembered that the reciprocator unit 20 provides two output signals to the reciprocator module 120. The first signal relates to the momentary closure of a limit switch (not shown) which represents that the spray gun assembly 22 has reached the bottom limit 30 of its travel. This provides a signal on the lead 27. This signal in the lead 27 is fed to a switch contact control circuit 130 which is fed to the reset terminal of reversible vertical counter 132. The switch contact control circuit 130 is identical to the switch contact control circuit 15 associated with the input module. The second signal received which is indicative of the position of gun assembly 22 is from the transducer 36. When the bottom limit switch is actuated, the reversible counter 132 is reset to zero and is directed to count upward. Thereafter, pulses from the rotary transducer 36 (representative of the vertical increments of travel of the gun assembly 22) sequence the vertical counter upward and through the zone patch numbers. In FIG. 3, it can be seen that a count between 7 and 12 is indicative of zone 1 while a count between 12 and 2i in the vertical counter 132 would be indicative of zone 2, etc. As the vertical counter 132 is passing through the individual sensing zones, as patched by die zone patch 122, a signal is placed on the input lead 128 corresponding to the zone represented by the count in vertical counter 132. If a signal happens to be present on any one of the leads 118, 1180, etc., corresponding to that same zone, the associated spray gun will be energized.

When the spray gun assembly 22 reaches the top of its stroke, an additional patch number represented by direction reversing patch 123 is encountered. This is the turnaround location above zone 10 (FIG. 3) and it directs the vertical reversible counter 132 to start counting downward. This reversal is accomplished by applying a trigger pulse to the input of a directional control flip-flop 134 which then pulses the vertical counter via the lead 135. Thus, as the reciprocator moves downward, the zones are scanned in reverse from what they would have been for the upward movement as is shown in FIG. 3.

With the basic configuration of the electronic control circuit 40 as well as the spray coating system 10, now in mind, a detailed description of the operation of the spray coating system 10 will now be described in connection with FIGS. 1 through 7. Assuming for the moment that we desire to coat a single object 14 and that this object has a vertical height such that it would eclipse four photocells and furthermore, let us assume that its horizontal width is such that it is representative of four increments of travel, i.e., a photocell will be eclipsed for the length of time necessary to move four increments, of travel, the description will then take place with this in mind. As the conveyor 12 moves, carrying the object to be coated 14, it drives the rotary transducer 17. The output from the rotary transducer 17 is fed to the switch contact control circuit l and provides distinct output pulses on the leads l9 and 89. These pulses are representative of the horizontal length of travel of the conveyor 12. If we assume whenever one of the photocells is eclipsed, or in a dark condition, the J-K flip-flop 68 is maintained in a set or one condition. With regard to the four-by-four part, the first four photocells 46a. 46b, 46c and 46d will remain in a dark or eclipsed condition for four increments of travel of the conveyor or, in other words, four pulses from the rotary transducer 17. These pulses cause a shifting action in the .l-K flip-flop 68 which provides a digital signal representative of the horizontal and vertical object dimensions. The shift pulses from the switch contact control circuit also initiate the sequencer routine through the flipflop 90. The digitized data information from the J-K flipflop 68 as well as from the leading edge register 72 and the lagging edge register 70 are fed into the write gate 84 and into the main memory 86 in a conventional manner where they are stored. It will be remembered that the main memory 86, an XY memory matrix, has a portion associated with each specific zone defined by the photocells that have been eclipsed, thus, retaining a digitized signal representative of the vertical height of the part. In addition, the number of bits stored in the matrix enables the memory 86 to maintain knowledge of the length of time that the photocell has been eclipsed, i.e., the horizontal dimension of the object. Information can only be written by the write gates 84 when the sequencer 94 is set on a count of 14 as shown in FIG. 5. When the sequencer 94 is set at a count of 14, the write gates 84 are enabled and the information from the shift register 66 is written into the main memory 86.

To start a sequence, as the shift pulses from the switch contact control circuit 15 occur, the flip-flop 90 and the sequencer clock 92 set the routine sequencer 94 to zero, thereby providing a signal to flip-flop 96 and the downline counter 98. This advances the address counter 100 to the downline location (in increments) for gun number 24c, that is, the spray gun which is furthest away from the photocell or, in other words, is the downline gun. The decoded zero output from the routine sequencer 94 is connected to the flip-flop 96 and the downline clock 98. The flip-flop 96 enables the downline ciock 98 to advance both the address counter 100 and the downline counter 104 in unison. The number of counts advanced by both counters is dependent upon the downline patching for the first or smallest number encountered in the downline counter. it will be remembered that the smallest number encountered in the downline counter 104 must correspond to the oldest information present in the main memory 86, and this information corresponds to the location of the gun 24c, i.e., the gun furthest from the sensor means 42. When this number is present in the downline counter 104 (represented by downline patch 83), the flip-flop 96 is reset halting both the downline counter [04 and the address counter 100. This action will occur within the one time slot (l millisecond as determined by the sequencer clock 92) owing to the relative speed of the clocks. The address counter [00 is now at the position in the memory desired to address the information with regard to gun number 24c. During the second count of the routine sequencer 94 (count of one) the clock leads for the buffer memory 88c associated with the gun 24c are energized so that data bits from the present selected address (gun 24c) of the main memory 86 are stored in the buffer memory 88c. This transfer is nondestructive owing to the way in which the memory chip is designed. The information from the main memory is then temporarily stored in the buffer memory until it is ready for further use. Thus, it can be seen that there are, in essence, two memories, the main memory and the buffer memory. The information in the buffer memory is a temporary storage and is designed to deliver the information relating to dimensions of the object to the gun location at the exact correct time when the part arrives in front of the gun iocation. However, since the individual guns are moving up and down as detennined by the reciprocator, each spray zone must be compared with the corresponding photocell sensing zone and the memory bits representative of the sensing zone in order to determine whether or not to spray paint at a given time.

After another millisecond count, the routine sequencer is advanced to a count of two, again enabling the flip-flop and the sequencer clock 92 and again advancing the downline counter 104 and the address counter I00 to next highest number which corresponds to the downline patch location for gun 24b and the position of memory 86 associated with gun 24b is addressed. Thereafter, the pattern just described repeats for all the remaining guns which, in this case, is a total of four. This takes the sequencer 94 through step 7. During step 8, the downline counter [04 and the address counter are again advanced for the last time during this cycle. The number sought is fixed at one count more than the total capability of the address counter. At the conclusion of this step, the address counter is always at N-H with respect to where it was prior to the shifl pulse. In the control circuit as built, the address counter has a maximum count of 64. Therefore, if this counter is advanced 65 counts during each routine, it will come to rest at N-H, where N is the count prior to the routine. When 65 is detected at the downline counter, by the patch 85, the flipflop 96 controlling the sequencer clock 92 is again turned off. In addition, the downline counter 104 is reset to zero as can clearly be seen in FIG. 6. This is required because, in order for the sequencing to work, the downline counter must be capable of counting to a number higher than 64 (the address counter capacity) and must always be reset to zero so mat the next cycle will be correct. It will be noticed, however, that the address counter 100 never has to be reset. It will also be noted that counts 9 through 13 of the sequence counter 94 are never used. However, this dead time" or nonuse of these counts may be reduced or lengthened to accommodate the size of the system and to compensate for typical component variations in clock rates.

As described earlier, during the routine sequencer 94's count of 14, the write gates 84 are enabled so that new data may be stored at an address of N+l This routine has the effect of converting the main memory 86 into a large shift register without the necessity of utilizing expensive shift registers and without the necessity of using a shift register for each zone which is defined. When the new data is written into the main memory 86, the old data is finally lost. When the 16th millisecond (count number 15) in the routine sequencer 94 occurs, the flip-flop 90 controlling the sequencer clock 92 is reset stopping the cock 92. This completes the routine. At this time, data for all four guns is available in the buffer memories 88 through 88c. Bits from the buffer memories 88 through 88c are presented to their respective zone gates 124 through 124C on a sustained basis. However, because the zone gates require two signals on the inputs, this information does not automatically actuate the respective spray guns. It is first necessary to compare the information from the buffer memories to the current position of the reciprocator 20 and thus, determine when a particular spray gun shall be energized.

Before discussing in detaii the method in which the vertical position of the spray gun can be ascertained, it is helpful to reflect back and to see the function of the counters and the main memory in the overall operation of the system. Both the address counter 100 and the downline counter 104 act in cooperation to decode or interrogate the main memory 86 and pass the information which had been stored in the main memory 86 to the buffer memories 88 through 88c. This then completes the function of the memory module since the digitized information representative of the dimensions of the object to be sprayed has been transmitted to the reciprocator module 120.

Feedback from the reciprocator unit 20 identifies the instantaneous position of the spray gun assembly 22. As mentioned before, this is accomplished through the use of the transducer 36 and the limit switch (not shown). The signals from each of these pass through switch contact control circuits I36 and X30, respectively, which are identical to switch contact control circuit 15, and provide pulses to the vertical counter 132. As the limit switch closes, the vertical counter 132 is set to zero and a directional control flip-flop 134 is reset so that the counter will subsequently count upwards. As the reciprocator moves upwards through the zones, the counter responds accordingly, keeping track of the instantaneous position. For zones, as shown in FIG. 3, l 1 numbers are patched which define the limits of each zone and when a match occurs between the number in the vertical counter 132 and a patched number as represented by the zone patch 122, the respective zone gates 124 through 124:: which contain the information representative of the match are set and the gunactuating control circuits 126 though 126C associated therewith actuates the respective spray gun. Zone gate 124 which has been set remains in that condition until a new match is encountered at the next patched number. When the top of the uppermost zone occurs, the zone flip-flops 124 through 114C are reset and the spraying ceases. As the reciprocator continues upward nearing the top, the turnaround patched number as represented by direction reversing patch number 123 is encountered. This reverses the direction of counting of the vertical counter 132 by triggering the directional control fliptiop 134 so that subsequently the counter 132 will count downward. It can be seen in FIG. 3 that this has the effect of actually lifting the travel zones upwardly with respect to the previous zones when the turnaround occurs ahead of dead center point 28. This effect is known as towing and is desirable because the towing action of the reciprocator which cants the travel aids in the uniform coating of the parts since the coating coming from the spray guns does not strike the parts in a horizontal plane and this aids in the angleof mist as it leaves the spray gun nozzle. Because the turnaround patching is a separate and isolated function, great variations in operation and in the angle of towing are possible and furthermore, since each spray zone dimension is in a separate patch 122, the zones need not be alike. While the control as shown has been equipped with four spray guns 2.4 through 24c, and I0 zones, 64 horizontal increments. and l 1 1 vertical increments. these numbers are completely arbitrary and should not be considered as limiting.

Referring to FIGS. 1, 4, 5, 6 and 7, it can be seen that the entire electronic control circuit 40 is of modular construction and is very economical to manufacture. Furthermore, since this is a digital system, it is relatively immune to variations in conveyor or reciprocator speeds. The component parts of the electronic control circuit 40 are all conventional and may be readily purchased from various manufacturers. A full description including wiring diagrams of the electronic spray control 40 may be found in an Amtron publication published on Oct. 9, I969, entitled "instruction Manual For Multilevel Spray System.

One embodiment of an electronic control circuit 40 which meets the above requirements contains the following exemplary components; however, it is to be recognized that these cornponents are merely illustrative of the invention and various modifications may be made without departing from the spirit spray guns upward for up travel and downward for down and the scope of the invention.

Element Manutacturers name and part number Quantity J-K flip-flop 68 Signetlcs SP 322-B, duel J-K flip-flop lfzone. Lag ing edge register 70 Fairchlld FC 9300, 4 bit shift register.-. 1. Loading edge register 72 Fair-child FC 9300, 4 bit shift register 1. Write gates 84 M- Bignetics SP 370-A, triple three input N0 R. gate. 3/zone Main memory 86.. Motorola MO 40051,, 16 bit scratch pad memory" tlzone Butler memory 88... Slgnetics N 8828A, dual D flip-flop 2/zons Signetlcs SP 322D, dual J-K flip-flop 3. Address counter 100 (+64) Signetics SP 380, quad 2 input NO R gate 1. Slgnetics N 8880, quad 2 input NAND gate. 2. Falrchild FC 9316, 4 bit binary up counteL 1. Route sequencer 94 (+16) Fairchild FC 9301, 1/10 decoder 1. Signetics N 8816, dual 6 input NAND gate." 1. Sequencer clock 92 (IMS) Fairehlld FC 9601, rnonostable rnultivibrator... 1. Downline clock 98 (10MB) Fairehild FC 9601, monostable rnuitivlbrator". 1. Fairchlld FC 9316, 4 bit giinary of: counter. Downline counter 104 (+128 modified to count to 65) gggggggtlgggg; 3,33 53,333; Signetics N 8880, quad 2 input NAND gate 1. 66 count. detector 85 S1 atios SP 317A, dual 4 input expandable N 0R. get 1. By Vania SM 188, tip/down a bit binary counter U 1. Fairchild FC me, u (down BOD counter.-. 1. Reversible vertical counter 132 (e111) Faimmm F0 93" 1 m decoder" 7. Fairchild FC 9315, 1/10 decoder. 1. Zone gates 124 Siguetics SP 380A, quad 2input R gate t/zone/gun. Gun actuator control circuit 126 Amtron ER series relay for energizing spray gun solenoid. l/gun. Directional control flip-flop 134 Signetlcs SP 322B, due J-K binary 1.

1 Equivalent to one buficrfgun/zone. u

in summary, therefore, it can be seen that electronic control circuit comprises one photocell amplifier 64 per photocell or sensing zone, one Jl( flipflop 68 per sensing zone, one lagging edge register 70 per sensing zone, one leading edge register 72 per sensing zone, one write gate 84 per sensing zone, one main memory per sensing zone, one buffer memory 88 per gun per sensing zone, one address counter 100, one sequencer 94, one downline counter 104, one sequencer clock 92, one flip-flop 90, one downline clock 98, one flipflop 96, one downline patch 83 per gun, one zone gate 124 per gun per zone, one vertical counter 132, and one gun-actuating control circuit 126 per gun. it should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

What is claimed is:

l. in a spray coating system of the type including a spray station, with at least one spray gun assembly having at least one spray gun thereon, and conveyor means for transporting objects of diverse geometry past said spray station, control apparatus comprising:

input means including a sensing device, positioned a predetermined distance in advance of said spray station, for developing predetermined signal information related to die dimensions of an object moving on said conveyor means past said sensing device;

first memory means, including a memory storage matrix for storing said signal information related to the dimensions of said object;

an actuating means associated with each of said spray guns and responsive to a predetermined input signal for operating its associated spray gun for a time interval related to the duration of said input signal;

a second memory means associated with each of said spray guns and connected between said first memory means and the actuating means associated with its respective spray gun, wherein each of said second memory means produces a signal which is introduced into the input of its associated actuating means; and

means for selectively interrogating said first memory means when said sensed object is advanced by said conveyor means to a predetermined position with respect to each of said spray guns whereby said signal information in said storage matrix is selectively transferred to said second memory means.

2. The control apparatus of claim 1 wherein said input means comprises means for generating a sequence of digitized information signals related to the dimensions of each object.

3. The control apparatus of claim 2 further comprising:

a plurality of said sensing devices spaced vertically relative to the direction of motion of said conveyor means to thereby define a corresponding plurality of vertically spaced sensing zones;

:1 reciprocator carriage for continuously transporting said spray gun assembly between predetermined first and second vertical limits; and

means for developing a reciprocator signal indicative of the vertical zone location of each of said spray guns on said spray gun assembly,

4. The control apparatus of claim 3 further comprising means for comparing said vertical zone position of each of said spray guns with said dimensions of said sensed object and with said position of said sensed object and producing said predetermined input signal for said actuating means only when said sensed object and said spray gun are in a predetermined position relative to each other.

5. The control apparatus of claim 4 wherein said comparing means comprises logic means associated with each of said spray guns and connected between the output of said second memory means, the output of said reciprocator signal means and the input of said actuating means wherein said logic means provides said predetermined input signal to said actuating means only when said reciprocator signal and said signal from said second memory means indicate that said sensed object and said spray gun are in said predetermined position relative to each other.

6. The control apparatus of claim 5 wherein said means for developing said reciprocator signal comprises:

a first signal generator means for developing an output signal pulse for each incremental unit of travel of said reciprocator carriage;

zone patch means for identifying each spray zone through which said reciprocator travels; and

vertical counter means adapted to be incremented by said first signal generator means wherein said reciprocator signal is produced at the output of said vertical counter means when said number of pulses stored in said vertical counter means equals said patch means for one of said spray zones.

7. The control apparatus of claim 6 wherein said predetermined input signal for said actuating means is produced only when said signal from said second memory means corresponds to said sensed object having passed through a vertical sensing zone corresponding to said vertical spray zone represented by said reciprocator signal.

8. The control apparatus of claim 7 wherein said vertical counter is reversible and wherein said means for developing said reciprocator signal further comprises:

a second signaLgenerating means for resetting said vertical counter to zero when said reciprocator carriage reaches said first vertical limit; and

means for reversing said vertical counter when said reciprocator carriage reaches said second vertical limit wherein said means for developing said reciprocator signal is thereby responsive to both directions of travel of said reciprocator carriage.

9. The control apparatus of claim 2 wherein said interrogating means comprises:

address counter means adapted to select the location of said signal information in said first memory means; and

decoder means adapted to sequentially advance said address counter means to enable said address counter means to select said information location in said memory storage matrix corresponding to each of said spray guns and further adapted to enable said information located by said address counter means to be transferred to the second memory means associated with said spray gun being addressed.

10. The control apparatus of claim 9 wherein said decoder means comprises:

a downline counter means;

patch means associated with said downline counter means for identifying the downline position of each of said spray guns with respect to said sensing devices; and sequencing means adapted to advance said address counter and said downline counter means until the total count stored in said downline counter means corresponds to the downline position of one of said spray guns and wherein said downline counter produces a pulse stopping said address counter and thereby enabling said address counter to locate said digitized signal information corresponding to said spray gun.

1]. The control apparatus of claim [0 wherein said sequencing means enables said second memory means associated with said spray gun to receive said information located by said address counter means after said address counter means has stopped.

12. The control system of claim 11 wherein said sequencing means is adapted to enable said first memory means to receive new information signals from said input means after said ad dress counter means has located the information corresponding to each of said spray guns.

13. The control apparatus of claim 12 wherein means are provided for resetting said downline counter and said sequencing means after said second memory means has received said information corresponding to each of said spray guns.

14. The control apparatus of claim 2 wherein said means for providing said digitized information signal further comprises a shift register having a plurality of serially connected stages wherein said signal information related to the dimensions of said object is fed into one of said stages.

15. The control apparatus of claim 14 wherein said shift register is adapted to provide a leading edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object.

16. The control apparatus of claim 15 wherein said shift register is adapted to provide a lagging edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object.

17. In a spray coating system of the type including a spray station, with at least one spray gun assembly having at least one spray gun thereon, and conveyor means for transporting objects of diverse geometry past said spray station, control apparatus comprising:

a plurality of sensing devices spaced vertically relative to the direction of motion of said conveyor means thereby defining a corresponding plurality of vertically spaced sensing zones, said sensing devices being positioned a predetermined distance in advance of said spray station for developing predetermined signal information related to the dimensions of an object moving on said conveyor means past said sensing devices;

shift register for receiving said signal information from said sensing devices and for generating a sequence of digitized information signals related to the dimensions of said object;

first memory means, including a memory storage matrix for storing said digitized signal information related to the dimensions of said object;

a reciprocator carriage for continuously transporting said spray gun assembly between predetermined first and second vertical iimits;

means for developing a reciprocator signal indicative of the vertical zone location of each of said spray guns on said spray gun assembly;

an actuating means associated with each of said spray guns and responsive to a predetermined actuating input signal for operating its associated spray gun for a time interval related to the duration of said actuating input signal;

second memory means associated with each of said spray guns and connected between said first memory means and the actuating means associated with its respective spray gun, wherein each of said second memory means produces a signal indicative of die position of said sensed object and the dimensions of said sensed object;

means for selectively interrogating said first memory means when said object is advanced by said conveyor means to a predetermined position with respect to each of said spray guns whereby said digitized signal information in said storage matrix is selectively transferred to said second memory means; and

means for comparing said reciprocator signal with said signal from said second memory means wherein said comparing means provides said predetermined actuating input signal to said actuating means only when said reciprocator signal and said signal from said second memory means indicates that said sensed object and said spray gun are in said predetermined position relative to each other.

18. The control apparatus of claim 17 wherein said means for developing said reciprocator signal comprises:

a first signal generator means for developing an output signal pulse for each incremental unit of travel of said reciprocator carriage;

zone patch means for identifying each spray zone through which said reciprocator travels;

vertical counter means adapted to be incremented by said first signal generator means wherein said reciprocator signal is produced at the output of said vertical counter means when said number of pulses stored in said vertical counter means equals said patch means for one of said spray zones.

19. The control apparatus of claim 18 wherein said actuating input signal for said actuating means is produced by said comparing means only when said signal from said second memory means corresponds to said sensed object having passed through a vertical sensing zone corresponding to said vertical spray zone represented by said reciprocator sigtal.

20: The control apparatus of claim 19 wherein said vertical counter is reversible and wherein said means for developing said reciprocator signal further comprises:

a second signal-generating means for resetting said vertical counter to zero when said reciprocator carriage reaches said first vertical limit; and

means for reversing said vertical counter when said reciprocator carriage reaches said second vertical limit wherein said means for developing said reciprocator signal is thereby responsive to both directions of travel of said reciprocator carriage.

21. The control apparatus of claim 20 wherein said interrogating means comprises:

address counter means adapted to select said signal information in said first memory means, and decoder means adapted to sequentially advance said address counter means to enable said address counter means to select said information location in said memory storage matrix corresponding to each of said spray guns and further adapted to enable said information located by said address counter means to be transferred to the second memory means associated with said spray gun being addressed. 22. The control apparatus of claim 21 wherein said decoder means comprises:

a downline counter means; patch means associated with said downline counter means for identifying the downline position of each of said spray guns with respect to said sensor means; and a sequencing means adapted to advance said address counter and said downline counter means until the total count stored in said downline counter means corresponds to the downline position of one of said spray guns and wherein said downline counter produces a pulse stopping said address counter and thereby enabling said eddies counter to locate said digitized signal information corresponding to said spray gun. 23. The control apparatus of claim 22 wherein said sequencing means enables said second memory means as- 0 sociated with said spray gun to receive said information located by said address counter means after said address counter means has stopped and enables said first memory means to receive new information signals from said shift register after said second memory means has received said information corresponding to each of said spray guns.

24. The control apparatus of claim 23 wherein means are provided for resetting said downline counter and said sequencing means after said second memory means has received the information corresponding to each of said spray guns.

25. The control apparatus of claim 24 wherein said shift register is adapted to provide a leading edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object.

26. The control apparatus of claim 25 wherein said shift register is adapted to provide a lagging edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object.

i i l i 1 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 Inventor(s) Vlr-g-Lei Porter It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

A Columns 11 and 12, line 6 of the chart, under the heading "Quantity", the footnotefl" shou ld be indieated.

Signed and sealed this 11th day of July 1972.

(SFAL) Attest:

R0 BERT GOTTSCHALK Attesting Officer Commissionerof Patents 

1. In a spray coating system of the type including a spray station, with at least one spray gun assembly having at least one spray gun thereon, and conveyor means for transporting objects of diverse geometry past said spray station, control apparatus comprising: input means including a sensing device, positioned a predetermined distance in advance of said spray station, for developing predetermined signal information related to the dimensions of an object moving on said conveyor means past said sensing device; first memory means, including a memory storage matrix for storing said signal information related to the dimensions of said object; an actuating means associated with each of said spray guns and responsive to a predetermined input signal for operating its associated spray gun for a time interval related to the duration of said input signal; a second memory means associated with each of said spray guns and connected between said first memory means and the actuating means associated with its respective spray gun, wherein each of said second memory means produces a signal which is introduced into the input of its associated actuating means; and means for selectively interrogating said first memory means when said sensed object is advanced by said conveyor means to a predetermined position with respect to each of said spray guns whereby said signal information in said storage matrix is selectively transferred to said second memory means.
 2. The control apparatus of claim 1 wherein said input means comprises means for generating a sequence of digitized information signals related to the dimensions of each object.
 3. The control apparatus of claim 2 further comprising: a plurality of said sensing devices spaced vertically relative to the direction of motion of said conveyor means to thereby define a corresponding plurality of vertically spaced sensing zones; a reciprocator carriage for continuously transporting said spray gun assembly between predetermined first and second vertical limits; and means for developing a reciprocator signal indicative of the vertical zone location of each of said spray guns on said spray gun assembly.
 4. The control apparatus of claim 3 further comprising means for comparing said vertical zone position of each of said spray guns with said dimensions of said sensed object and with said position of said sensed object and producIng said predetermined input signal for said actuating means only when said sensed object and said spray gun are in a predetermined position relative to each other.
 5. The control apparatus of claim 4 wherein said comparing means comprises logic means associated with each of said spray guns and connected between the output of said second memory means, the output of said reciprocator signal means and the input of said actuating means wherein said logic means provides said predetermined input signal to said actuating means only when said reciprocator signal and said signal from said second memory means indicate that said sensed object and said spray gun are in said predetermined position relative to each other.
 6. The control apparatus of claim 5 wherein said means for developing said reciprocator signal comprises: a first signal generator means for developing an output signal pulse for each incremental unit of travel of said reciprocator carriage; zone patch means for identifying each spray zone through which said reciprocator travels; and vertical counter means adapted to be incremented by said first signal generator means wherein said reciprocator signal is produced at the output of said vertical counter means when said number of pulses stored in said vertical counter means equals said patch means for one of said spray zones.
 7. The control apparatus of claim 6 wherein said predetermined input signal for said actuating means is produced only when said signal from said second memory means corresponds to said sensed object having passed through a vertical sensing zone corresponding to said vertical spray zone represented by said reciprocator signal.
 8. The control apparatus of claim 7 wherein said vertical counter is reversible and wherein said means for developing said reciprocator signal further comprises: a second signal-generating means for resetting said vertical counter to zero when said reciprocator carriage reaches said first vertical limit; and means for reversing said vertical counter when said reciprocator carriage reaches said second vertical limit wherein said means for developing said reciprocator signal is thereby responsive to both directions of travel of said reciprocator carriage.
 9. The control apparatus of claim 2 wherein said interrogating means comprises: address counter means adapted to select the location of said signal information in said first memory means; and decoder means adapted to sequentially advance said address counter means to enable said address counter means to select said information location in said memory storage matrix corresponding to each of said spray guns and further adapted to enable said information located by said address counter means to be transferred to the second memory means associated with said spray gun being addressed.
 10. The control apparatus of claim 9 wherein said decoder means comprises: a downline counter means; patch means associated with said downline counter means for identifying the downline position of each of said spray guns with respect to said sensing devices; and a sequencing means adapted to advance said address counter and said downline counter means until the total count stored in said downline counter means corresponds to the downline position of one of said spray guns and wherein said downline counter produces a pulse stopping said address counter and thereby enabling said address counter to locate said digitized signal information corresponding to said spray gun.
 11. The control apparatus of claim 10 wherein said sequencing means enables said second memory means associated with said spray gun to receive said information located by said address counter means after said address counter means has stopped.
 12. The control system of claim 11 wherein said sequencing means is adapted to enable said first memory means to receive new information signals from said input means after said address counter means has located the information corresponding to each of said spray guns.
 13. The control apparatus of claim 12 wherein means are provided for resetting said downline counter and said sequencing means after said second memory means has received said information corresponding to each of said spray guns.
 14. The control apparatus of claim 2 wherein said means for providing said digitized information signal further comprises a shift register having a plurality of serially connected stages wherein said signal information related to the dimensions of said object is fed into one of said stages.
 15. The control apparatus of claim 14 wherein said shift register is adapted to provide a leading edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object.
 16. The control apparatus of claim 15 wherein said shift register is adapted to provide a lagging edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object.
 17. In a spray coating system of the type including a spray station, with at least one spray gun assembly having at least one spray gun thereon, and conveyor means for transporting objects of diverse geometry past said spray station, control apparatus comprising: a plurality of sensing devices spaced vertically relative to the direction of motion of said conveyor means thereby defining a corresponding plurality of vertically spaced sensing zones, said sensing devices being positioned a predetermined distance in advance of said spray station for developing predetermined signal information related to the dimensions of an object moving on said conveyor means past said sensing devices; a shift register for receiving said signal information from said sensing devices and for generating a sequence of digitized information signals related to the dimensions of said object; first memory means, including a memory storage matrix for storing said digitized signal information related to the dimensions of said object; a reciprocator carriage for continuously transporting said spray gun assembly between predetermined first and second vertical limits; means for developing a reciprocator signal indicative of the vertical zone location of each of said spray guns on said spray gun assembly; an actuating means associated with each of said spray guns and responsive to a predetermined actuating input signal for operating its associated spray gun for a time interval related to the duration of said actuating input signal; second memory means associated with each of said spray guns and connected between said first memory means and the actuating means associated with its respective spray gun, wherein each of said second memory means produces a signal indicative of the position of said sensed object and the dimensions of said sensed object; means for selectively interrogating said first memory means when said object is advanced by said conveyor means to a predetermined position with respect to each of said spray guns whereby said digitized signal information in said storage matrix is selectively transferred to said second memory means; and means for comparing said reciprocator signal with said signal from said second memory means wherein said comparing means provides said predetermined actuating input signal to said actuating means only when said reciprocator signal and said signal from said second memory means indicates that said sensed object and said spray gun are in said predetermined position relative to each other.
 18. The control apparatus of claim 17 wherein said means for developing said reciprocator signal comprises: a first signal generator means for developing an output signal pulse for each incremental unit of travel of said reciprocator carriage; zone patch means for iDentifying each spray zone through which said reciprocator travels; vertical counter means adapted to be incremented by said first signal generator means wherein said reciprocator signal is produced at the output of said vertical counter means when said number of pulses stored in said vertical counter means equals said patch means for one of said spray zones.
 19. The control apparatus of claim 18 wherein said actuating input signal for said actuating means is produced by said comparing means only when said signal from said second memory means corresponds to said sensed object having passed through a vertical sensing zone corresponding to said vertical spray zone represented by said reciprocator signal.
 20. The control apparatus of claim 19 wherein said vertical counter is reversible and wherein said means for developing said reciprocator signal further comprises: a second signal-generating means for resetting said vertical counter to zero when said reciprocator carriage reaches said first vertical limit; and means for reversing said vertical counter when said reciprocator carriage reaches said second vertical limit wherein said means for developing said reciprocator signal is thereby responsive to both directions of travel of said reciprocator carriage.
 21. The control apparatus of claim 20 wherein said interrogating means comprises: address counter means adapted to select said signal information in said first memory means; and decoder means adapted to sequentially advance said address counter means to enable said address counter means to select said information location in said memory storage matrix corresponding to each of said spray guns and further adapted to enable said information located by said address counter means to be transferred to the second memory means associated with said spray gun being addressed.
 22. The control apparatus of claim 21 wherein said decoder means comprises: a downline counter means; patch means associated with said downline counter means for identifying the downline position of each of said spray guns with respect to said sensor means; and a sequencing means adapted to advance said address counter and said downline counter means until the total count stored in said downline counter means corresponds to the downline position of one of said spray guns and wherein said downline counter produces a pulse stopping said address counter and thereby enabling said address counter to locate said digitized signal information corresponding to said spray gun.
 23. The control apparatus of claim 22 wherein said sequencing means enables said second memory means associated with said spray gun to receive said information located by said address counter means after said address counter means has stopped and enables said first memory means to receive new information signals from said shift register after said second memory means has received said information corresponding to each of said spray guns.
 24. The control apparatus of claim 23 wherein means are provided for resetting said downline counter and said sequencing means after said second memory means has received the information corresponding to each of said spray guns.
 25. The control apparatus of claim 24 wherein said shift register is adapted to provide a leading edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object.
 26. The control apparatus of claim 25 wherein said shift register is adapted to provide a lagging edge spray control whereby said spray gun is operated for a preselected interval greater than or less than that established by said information signal related to the dimension of said object. 